The present invention relates generally to the field of electrical enclosures. More particularly, the invention relates to a technique for permitting access to components within an electrical enclosure, while providing a solid latching structure to maintain a door in a closed position, even during movement of the door to permit escape of internal gasses from the enclosure.
Many applications exist in industry and other settings for electrical components disposed in controlled-environment enclosures. In industrial applications, for example, sheet metal enclosures are commonly provided in which electronic and electric power components are disposed. The enclosures may be simple box-type structures or may be more complex cabinets having a number of compartments in which the components are positioned. In currently available enclosures, for example, both power and data signals may be routed to, from and between the components within the enclosure. In many applications, larger enclosures include routing for medium or high voltage power, including three-phase power that is applied to loads by appropriate switching of the components within the enclosure.
Depending upon the size and physical configuration of enclosures, various types of latching devices may be provided that permit doors to be reliably secured in place over a component opening. The doors are typically made of the same material as the remainder of the enclosure, and are hinged to permit access to the components. In certain designs, drawers or other retractable structures may be provided for mounting the components, and for removing, at least partially, the mounted components from the enclosure for servicing. Where smaller or more tightly packed component assemblies are present in the enclosures, the access may be encumbered by the latch mechanism itself. Accordingly, there is a need for improved latching mechanisms that permit both full access to components within an electrical enclosure, yet that allow for deployment for solidly latching a door that prevents access to the components.
There is also a need in the art for improved latch mechanisms for enclosures that permit the escape of gasses during certain periods of operation. For example, certain types of faults may occur within electrical enclosures, such as due to malfunctions in wiring, components, or both. During such malfunction, gasses may be suddenly and rapidly heated by electrical discharges. The hot gasses, including gasses resulting from vaporized wiring, installation and component structures, expand rapidly and must be permitted to escape from the enclosures in controlled ways. Standards have been developed as a guide to the manner in which such hot gasses are allowed to escape from enclosures. However, latches that permit the escape of gasses during component malfunction may further encumber the access to the internal electrical components. Accordingly, there is a need for improved non-encumbering latch mechanisms that nevertheless provide for escape of hot gasses from an enclosure during faults or abnormal events that may occur within the enclosure.